The present invention relates generally to the field of assemblies used to secure cargo. More particularly, the invention relates to a tie-down assembly used to secure cargo in place in or on a vehicle, trailer or container.
Various types and sizes of cargo are transported from a point of origin or an intermediary point to a destination. Independent of the type of transportation that is used to transport the cargo, the cargo can be subjected to a wide variety of forces from a wide variety of directions. Accordingly, it is important that the cargo be properly secured to whatever type of transportation is used to transport it. Traditionally, a variety of type of cargo tie-downs have been used to secure cargo.
The attachment points for cargo tie downs on load carrying vehicles are designed to retain the cargo safely in place during the operation of the vehicle. These tie-downs can be designed to hold the cargo securely and withstand the application of forces occurring during transportation.
For example, for commercial on-highway trucks of the flat-bed type, there are currently many different cargo securing systems commercially available, the most common being separate webbing straps terminating in “rave hooks” which hook on to the turned-in lower flange of the vehicle's chassis rails or the lower outboard edges of the cargo bed as their primary attachment points. The securing straps attach to the main chassis rails on one side, pass over and bear against the side edge of the cargo bed, over the cargo to be secured, over the opposite side edge of the cargo bed and attach to the lower chassis rail flange on the opposite side. Alternatively, the side edges of the cargo-bed have been used to secure the tie-down load. Where the side edges are used, the straps are hooked on one side of the bed, pass over the cargo to be secured, and attach to the other side of the bed.
On trucks or trailers fitted with side-boards of the fixed or drop-down type, the use of the chassis rails or cargo-bed edges as anchor points for tie-down straps can be inhibited by the presence of the sides. Moreover, on some trucks there may be no ready access to permit the frame rails to be used as anchor points. This is particularly true of military cargo trucks since the space adjacent to the chassis rails may be occupied by ancillary equipment such as winches, filters, fuel and hydraulic tanks and equipment storage. In such cases it is common practice to have a number of fixed tie-down anchor points on, or recessed into the cargo bed deck.
Contemporary practice relating to the restraint of cargo on military trucks differs from commercial on-highway practice. The loads imposed during operation of military trucks is often significantly higher than for commercial practice. During rapid off-road operation military trucks may have to sustain repeated vertical, lateral and longitudinal accelerations to the accepted limits of the driver's ability to endure them. Additionally, during ship-borne deployment, the loaded vehicle is chained down and can be subjected to high vertical accelerations and lateral accelerations in excess of the vehicle's normal lateral stability limits. Additionally, during transport of loaded vehicles by rail freight, a loaded vehicle can be subjected to longitudinal accelerations approaching 4g during automatic rail-car sorting which is conducted on a down grade—the so called “Rail Hump” condition. Because of these load cases, military cargo tie-downs are often required to satisfy more stringent specifications than those typically applied to commercial highway operation.
A number of types of recessed tie down assemblies for mounting in cargo-bed decks have traditionally been used. Traditional tie-down assemblies commonly have included a welded assembly that precludes the replacement of a damaged tie-down ring or bail by the use of normal hand tools. Traditional tie-down assemblies have also defined a space through the ring or bale that is insufficient to accept some of the hooks, chains and tie-down fittings in common use today. Additionally, traditional tie-down assemblies have not had the capability to accept wide metal banding as an optional tie-down medium.
Additionally, for traditional tie-down assemblies, during loading and positioning of the cargo by sliding, tie-down rings are kept folded in their recessed pockets in order to permit a fork-lift loading operation without risk of unnecessary damage to the tie-downs or cargo. The tie-down rings can be swung upwards to attach the tie-down straps or banding after loading is complete. However, if the cargo were to be placed over the folded-down edge of any of the tie-down rings, the rings can not be raised up for use and the tie-downs can be rendered inoperative. Because of the restriction this imposes while loading cargo, the usable width of the cargo-bed, especially for palletized or boxed cargo, is the width measurement between the innermost edges of the folded tie-down rings on opposite sides of the cargo-bed. The full width of the cargo bed or at least the width between tie-down ring pivot centers can not be utilized.
What is needed is a tie-down assembly that can be efficiently and inexpensively produced. What is further needed is a tie-down assembly whose parts can be easily removed and replaced. What is further needed is a tie down assembly including an aperture that is sufficiently sized to accommodate a variety of securing devices. What is yet further needed is a tie-down assembly that provides the capability of using traditional lashings or other lashings, such as wide metal banding to secure the load.